Stainless Steel Self Drilling (Tek) Screws

1. Stainless Steel Tek Screws (SelfDrilling Screws)

2. There are two main types of Stainless Steel Self-Drilling Screws – Self Drilling Screws for
Timber which often have a Type 17 style cutting flute and Self Drilling Screws for Metal
often called a Stainless Steel Tek Screw:
Here we are talking about the Self Drilling Screw for Metal often called a Stainless Steel
Tek Screw.

3. These are screws designed to self-drill into metal. There are several material types
available and they each have their strengths and weaknesses. Getting the material
right for your application is critical. Some Stainless Steel Grades have excellent
corrosion resistance (304 and 316) but are relatively soft and will not self-drill through
much more than the skin of a milk pudding! Other grades like 410 are heat treated
and have excellent hardness – but anywhere near salt-water (or any sort of coastal
atmosphere) and you will see some tea-staining pretty quick! Some grades such as
Hardtec and Marutex Stainless Steel feature the benefits of both (hardness and
excellent corrosion resistance) – but are only available in Hex Washer Face Head style.
Getting the right material grade and screw type for your application is critical.

4. 410 Stainless Steel Self Drilling Screws – These are completely Stainless Steel. 410 is a
Martensitic Stainless Steel and so can be hardened by heat treatment (which
Austenitic types 304 and 316 cannot be). For this reason it has excellent drilling
properties – however 410 has lower corrosion resistance than grade 304 and should
not be used in highly or even moderately corrosive environments or tea-staining will
result.

5. 304 and 316 Stainless Steel Self Drilling Screws – Because the 300 series of Stainless
Steels are of an Austenitic crystal structure – hardening by heat treatment is not
possible. These screws provide excellent corrosion resistance but are really only good
for self-drilling through thin aluminium due to the softness of the material.

6. Hardtec/Martuex Stainless Steel – Both ‘Hardtec’ and ‘Marutex’ grades of Stainless
Steel are propriety grades made specifically for Stainless Steel Self Drilling
Screws. They are hardened by heat treatment and so have excellent drilling
performance into metals like grade 410 BUT unlike grade 410, these grades have
Molybdenum added to them and have corrosion resistant properties in line with the
300 series Stainless Steel grades. Salt Spray tests show corrosion equal or better to
that of 304 Stainless Steel and not far behind 316 Stainless Steel. They are an excellent
screw!

7. For full article see:
Stainless Steel Tek Screws (Self-drilling Screws)